Conventionally, a navigation device employs a technique in which route guidance is performed by receiving input from a user whose route is to be guided by the navigation device. That is to say, operation of operating switches on a main unit or switching operation of a remote control is received as input information. Patent Document 1 describes a technique relating to such a navigation device.    Patent Document 1: Japanese Unexamined Patent Application Laid-Open No. 2009-143373